Frequency Calibration for Weak Signal Work
- Accurate calibration of your receiver and sound card is necessary for good results with the weak signal modes in use at LF. Modern receivers with master oscillators that are synthesized to provide all conversion frequencies greatly simplify the process. This article describes a method of making the necessary measurements and adjustments to an ICOM R75 receiver and a sound card, using the ARGO software

Phase Noise.
- This is perhaps the most important parameter in many oscillators and it deserves an in-depth discussion on what it is, how it affects a system and how it can be minimised in an oscillator design.

Voice Descramble
- This program descrambles band inverted encrypted transmissions, usually found on VHF/UHF. It uses a NCO (numerical controlled oscillator) to re-produce the originally inverted audio band.

SweepGen
- SweepGen turns a PC into an Audio Oscillator and Sweep Generator which can be used for testing audio or educational purposes. In conjunction with audio test instruments, you can make frequency response plots. SweepGen uses the sound card in your PC to produce sinewaves

Voice descrambler
- This program descrambles band inverted encrypted transmissions, usually found on VHF/UHF. It uses a NCO (numerical controlled oscillator) to re-produce the originally inverted audio band. Use it only if legally permitted in your country. I assume no responsabilities deriving from its use. Standard disclaimer applies

The Fox - 40mw transmitter
- This RDF two transistor 144 MHz transmitter uses a 48 MHz scanner crystal as an oscillator / tripler. A second transistor boosts the power output to 40 milliwatts.

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The Fox - 750 mw transmitter
- This RDF three transistor 144 MHz transmitter uses a 48 MHz scanner crystal as an oscillator / tripler. A second transistor boosts the signal to 40 milliwatts, a third amplifies the power output to 750 milliwatts.
Includes schematic and pictures.

A 6M Transverter
- Build a transverter based on a 6M receive converter. A 32MHz TTL oscillator is used as the local oscillator for both transmitting and receiving. RX/TX switching is handled by three SPDT relays.

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9cm transverter
- Designed for portable operation, it runs on 12v, and has an OCXO-based local oscillator.